<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
<style>
    *{margin:0;padding:0;}
    div{
        box-sizing: border-box;
    }
    .parent{
        margin-left:auto;
        margin-right: auto;
        background:#ff2d51;
        width:1000px;
        height:300px;
        font-size:0;
    }
    .parent>div{
        display: inline-block;
        width: 240px;
        height:300px;
        border:1px solid #333;
    }
    .parent>div:not(:last-child){
        margin-right:13.3333px;

    }
</style>
</head>
<body>
    <div class="parent">
    <div></div>
    <div></div>
    <div></div>
    <div></div>
    </div>
</body>
</html>